#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Sat Sep 16 14:00:42 2023

@author: liqingsimac
"""

import numpy as np
import matplotlib.pyplot as plt

x=np.linspace(0,np.pi/2,50)
y1=1/x
y2=np.sin(2*x)

fig=plt.figure()
ax=fig.add_subplot(111)
ax.plot(x,y1,'b-')
ax.plot(x,y2,'r--')
ax.set_ylim([-0.2,1.2])

ax.axvline(x=1)
ax.axhline(y=1)
ax.axvline(x=np.pi/3)

y3=-x+2
ax.plot(x,y3,'b-')
y4=-1*(x-np.pi/3)+np.sin(2*np.pi/3)
ax.plot(x,y4,'r--')

